Second, power saving, no high temperature: it is a low-power product, which can not generate heat at all, while CRT monitors will inevitably generate high temperature due to imaging technology.
Third, no radiation, good for health: LCD is completely radiation-free, which is good news for people who work in front of computers all day.
The application patent number is CN2004 10000423. X
Patent application date: 2004.0 1. 18.
A method for driving a cholesteric liquid crystal display.
Publication (announcement)No. CN 164 1735
Publication date (announcement) July 20, 2005
Category physics
Certification date
right of priority
Apply for (patent right) Qi Jing Optoelectronics Co., Ltd.
Address Tainan County, Taiwan Province Province
Inventor (designer) Chen Yansheng; Chen Jianbin; Lai jiacheng
International application
International announcement
date of entry
Patent Agent Beijing Jikai Intellectual Property Agency Co., Ltd.
Agent cheng Wei. Wang Jinyang
abstract
The invention relates to a method for driving a cholesteric liquid crystal display. A plurality of pixels in a cholesteric liquid crystal display provide required driving signals by using a plurality of row drivers and column drivers. The driving method of the invention firstly provides unipolar input power or asymmetric alternating current power to the row driver and the column driver, and increases the voltage applied to the pixel to be greater than the withstand voltage of the driver with low withstand voltage, and then the driver respectively provides the row initial signal and the column initial signal, and the polarities of the row initial signal and the column initial signal are opposite, so as to initialize the pixel. By using the driving method of the present invention, since the synthesized signal of these pixels is the column initial signal minus the row initial signal, the voltage amplitude of the signal applied to the pixel can be increased, thereby shortening the initial time of the pixel and improving the conversion speed of the pixel.
Sovereignty terms
1. A unipolar driving method for a cholesteric liquid crystal display having a plurality of row electrodes, a plurality of column electrodes, and a plurality of pixels located at intersections of the row electrodes and the column electrodes; These row electrodes are provided with required driving signals by at least one row driver with a first row power input terminal and a second row power input terminal; These column electrodes are provided with required driving signals by at least one column driver with a first column power input and a second column power input; The second column power input of the column driver is electrically connected with the first row power input of the row driver; The input power supply of the column driver and the row driver is unipolar, and the input power supply of the column driver and the corresponding row driver is opposite in polarity; The unipolar driving method comprises the following steps: a, a row driver outputs a row initial signal to a corresponding row electrode, and a column driver outputs a column initial signal to a corresponding column electrode, wherein the row initial signal and the column initial signal are unipolar signals, and the polarities of the row initial signal and the column initial signal are opposite to initialize corresponding pixels, so that the effective value of the synthesized initial signal of the corresponding pixel is increased to be greater than the maximum withstand voltage of the column driver and the row driver. B, the row driver outputs a row address signal, and the column driver outputs a column address signal, wherein the row address signal and the column address signal are unipolar signals, so as to control corresponding pixels and further display images.
Detailed explanation of driving principle of TFT LCD liquid crystal display
Driving principles of TFT LCD liquid crystal display (I), (II) and (III) series. The storage capacitor structure of TFT LCD panel Cs (storage capacitor), various polarity conversion modes of the panel, flicker avoidance, second-order driving and multi-order driving principles are introduced in detail, which is the basis for understanding TFT LCD panel and improving teaching materials.
Fourth, the picture is soft and does not hurt the eyes: unlike CRT technology, the picture of LCD will not flicker, which can reduce the damage of the display to the eyes, and the eyes are not easily tired.
Liquid crystal display is green and environmentally friendly, and the energy consumption is simply too small compared with traditional CRT; The noise pollution that gradually attracts people's attention has nothing to do with it, because its own working characteristics determine that it will not produce noise (the noise that users like to beat the monitor rhythmically when using the computer is not considered here); Another advantage of LCD is that its calorific value is relatively low, and it won't feel hot when used for a long time, which is incomparable to previous displays. In the past, the monitor was very precious, especially in summer, and the air conditioner and electric fan at home had to serve it to cool it down. The use of liquid crystal display invisibly reduces the temperature of the atmosphere and helps to prevent the temperature of the atmosphere from rising. At the same time, reduce radiation and environmental pollution. Of course, environmental protection will not lose the index of radiation. Although it can't be said that LCD has no radiation at all, compared with CRT, the radiation of LCD can be ignored.
The present era is actually an analog era, and the future era is a digital era from the current development trend. Intelligent display operation, digital control and digital display are necessary conditions for future displays. With the advent of the digital age, digital technology will completely replace analog technology, and liquid crystal display will soon completely replace the current analog CRT display.
On the other hand, the digital interface of LCD is not popular now, which is far from the application field. Theoretically, LCD is a pure digital device, and the connection with the computer host should also adopt a digital interface. The advantages of adopting digital interface are self-evident. Firstly, it can reduce the signal loss and interference in the process of analog-to-digital conversion; Reduce the corresponding conversion circuits and components; Secondly, there is no need to adjust the clock frequency and vector.
However, at present, the interfaces of most liquid crystal displays in the market are analog interfaces, and there are some problems, such as the transmission signal is easily disturbed, the analog-to-digital conversion circuit needs to be added in the display, and it cannot be upgraded to digital interfaces. In addition, in order to avoid pixel flicker, the clock frequency and vector must be completely consistent with the analog signal.
In addition, the digital interface of LCD has not yet formed a unified standard, and graphics cards with digital output are rare in the market. This makes it difficult to give full play to the key advantages of LCD.
This question may not be easy to understand. Let's give an example to illustrate. Anyone who has used liquid crystal displays knows that liquid crystal displays are prone to image tailing.
Response time is a special index of LCD. The response time of liquid crystal display refers to the speed at which each pixel of the display reacts to the input signal. If the response time is short, the image tailing phenomenon will not appear when the moving picture is displayed. This is very important when playing games and watching fast-moving images. Fast enough response time can ensure the continuity of the picture. At present, the response time of ordinary liquid crystal displays on the market has made a great breakthrough compared with before, generally around 40 ms, but with the development of technology, the gap between LCD and CRT has been gradually made up. The response time of a new high-brightness LCD of Meger Technology is shortened to 20ms, but Meger's goods are good and the price is good, which is several hundred yuan higher than that of ordinary LCD. However, even 20ms Meg is not comparable to almost any CRT at present.
Therefore, if you like to play 3D games and watch intense movies, LCD may hinder you because of its slow response time.
From the appearance, the LCD is thin and ultra-thin. Compared with the traditional spherical display, its thickness and volume are only half that of CRT display (for example, Acer's FP58 1, and its thickness is even smaller than that of ordinary CRT display 1/5), which greatly reduces the occupied space.
Hong Kong and Tokyo have the highest penetration rate of LCD monitors in the world. Last year, Hong Kong's LCD shipments accounted for 70% of the total display shipments. It is not difficult to find that most of these places are prosperous and crowded, with high living standards and many office buildings and financial buildings. In these places, it is an inch of land and gold. The land price of the space saved by the display is much higher than the price difference between LCD and CRT. At present, the prosperous areas of some big cities in Chinese mainland are also developing in this direction.
This question is actually about your use of the monitor. As we all know, because liquid crystal molecules themselves cannot emit light, liquid crystal displays need to rely on external light sources to assist in emitting light. Generally speaking, 140 lumens per square meter is enough. There is still a gap between the parameter standards of some manufacturers and the actual standards. It should be explained here that some small-sized LCD monitors were mainly used in notebook computers, and the adjustment of two lights, brightness and contrast were not very good. The brightness of mainstream desktop LCD can reach 250 lumens to 400 lumens, which has gradually approached the level of CRT.
For most people, if you put CRT and LCD together, you can easily tell the difference between LCD and ordinary CRT in brightness, contrast and color saturation, but in general use, this little difference will not affect your work.
But for professional artists and other jobs that require accurate colors, LCD can't fully meet their job requirements.
Ordinary liquid crystal displays are divided into four types according to their physical structures:
(1) twisted nematic type;
(2) super twisted nematic (STN-Super TN);
(3)DSTN- double scanning torsion without graphics;
(4)TFT- thin film transistor.
1.TN adopts the most basic display technology in LCD, and other types of LCD are also improved on the basis of TN. And its working principle is simpler than other technologies. Please refer to the figure below. The figure shows a simple structural diagram of TN liquid crystal display, including vertical and horizontal polarizers, alignment films with thin lines and grooves, liquid crystal materials and conductive glass substrates.
2.2 display principle. STN is similar to TN. The difference is that TN twisted nematic field effect liquid crystal molecules rotate the incident light by 90 degrees, while STN super twisted nematic field effect rotates the incident light by 180 ~ 270 degrees.
3.DSTN distorts the nematic liquid crystal display screen by double scanning, so as to achieve the purpose of display. DSTN is developed from super twisted nematic display (STN). Because DSTN adopts double scanning technology, the display effect is greatly improved compared with STN.
4.TFT LCD is complex, mainly composed of fluorescent tubes, light guide plates, polarizers, optical filters, glass substrates, alignment films, liquid crystal materials, thin transistors and so on. First of all, the LCD should first use the backlight, that is, the fluorescent tube projects the light source, which will pass through a polarizer and then through the LCD. At this time, the arrangement of liquid crystal molecules will change the angle of light passing through the liquid crystal, and then these light must pass through the front color filter film and another polarizer. Therefore, we can control the final light intensity and color only by changing the voltage applied to the liquid crystal, so as to change the color combination of different tones on the liquid crystal panel. It is the panel of mainstream liquid crystal display at present.